How to use group by function

The GROUP BY function groups data by column values ​​and applies aggregate functions (such as SUM) operations to display unique values ​​and aggregate results for each group.

GROUP BY function

The GROUP BY function allows you to group rows in a dataset based on one or more common column values.

grammar

 <code>SELECT 列名, 聚合函数(列名) FROM 表名GROUP BY 列名</code>

parameter

• Column name: The column to be grouped.
• Aggregation function: Aggregation functions applied within each group, such as SUM, COUNT, AVG, etc.

usage

• After grouping the datasets, the aggregate function will perform operations on the values ​​in each group.
• In the result set, the unique values ​​for each group and the calculation results of the aggregate function will be displayed.

Example

Consider the following dataset:

Order number	product	unit price	quantity
1	Product A	10	5
2	Product B	12	3
3	Product A	15	2
4	Product B	18	1
5	Product C	20	4

To calculate the total sales of each product, you can use the following GROUP BY query:

 <code>SELECT 产品, SUM(数量* 单价) AS 总销售额FROM 销售数据GROUP BY 产品</code>

result:

product	Total sales
Product A	130
Product B	42
Product C	80

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